Window cutting precise measurements - beginner question!

[tw1984]

Hi everyone. I'm new here. New to framing. I have myself a second hand Keencut Ultimat Futura 1200.

First project is framing a small strip of passport photos.
Cropped image size is 97mm x 43mm.
I cut the window to this size, but it still cropped too tightly on my photograph.
What I realised is that I hadn't taken into account the width of the bevel (guessing it's about 1mm), which encroaches on the image.
So my question is - if framing something where I have to be extremely exact, should I add a 1mm allowance all round to my window measurements?
I cut a new piece of matboard with a bigger window (99x45) and the fit is good for me.

Hopefully my images below are useful to explain the situation!

Thanks!
tw

 

[RoboFramer]

The aperture is the aperture and should not include any of the bevel and is the size of the board minus the mat width.. it’s those dimensions that need to be accurate, so, assuming your board is bang on, your mat width also has to be.

Calibrate your mat guide so that is the case. Eg If you set it to 80mm and it gives you 81mm, dial the stop’s cursor to 81mm then reset the stop to 80.

 

[tw1984]

Thank you @RoboFramer, I appreciate the reply. Makes sense - I've calibrated everything and I think I'm good

 

[Rick Granick]

Rather than using the measuring stops, carefully measure and draw the opening dimensions on the back of the mat and cut to those. Practice first to observe if there is any offset of the blade away from the cutter bar, and orient your drawn cutlines taking that into account when cutting.
Rick
Cutting tip: Remember, the mat fallout will always be under the cutter bar.

 

[alacrity8]

It's interesting to see that you list art size, and top of bevel.
This makes me ask the question of whether you are cutting from the front or the back.
You should definitely be cutting from the back. The size you want is the bottom of the bevel, which would likely be 44 mm on your final version.

You never want to cut exact size of the art.
If the art has no border, then if you cut exact size, your art will fall through.
If the art has a border, there will always be a tiny spot where the area outside the border shows.
It is better to show a bit of space past the border (as you did), or cover a tiny amount all around the art.

 

[David Waldmann]

It is better to show a bit of space past the border (as you did), or cover a tiny amount all around the art.

We call that a "frog's hair".

Actually, we used to. Now we're all grown up and use real measurements, like 1/1000", 2/1000", 3/1000", etc.